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The project site has level terrain; consequently, there is no need to incorporate design considerations for slopes within the effluent disposal area. B. SOIL PHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTS SSS§ 5.2. The UC Davis Soil Web designates the soil as a Capay Clay(#118): 85% Capay clay, 5% Stomar clay, 4% Willows clay, 4%Vernalis clay. Texture analysis show the soils at 36" below grade in the proposed filter bed area to be a clay loam (clayey silt). NLS§ 1.1, 1.2. The surface and subsurface soil investigation began on May 24, 2022 with-the drilling of one 36-inch deep perc test boring. Auger cuttings were sampled for laboratory analysis from this depth. •As noted on the Soil Report in Appendix B, chemical analysis of the soil samples quantifies a number of constituents that influence nitrate loading for this project. The important parameters for nitrate loading assessment are the organic matter,pH, cation exchange capacity (CEC), and the nitrate-nitrogen content of the soil. Additional chemistries were also conducted for loading assessment including the carbon-nitrogen(C:N)ratio, organic carbon and Total Nitrogen (TN). Although the TN was relatively high, the C:N ratio was 8.2 which is low enough to impede nitrification and promote denitrification. The soil nitrate-nitrogen concentration is a medium concentration at 13 ppm at the 36" depth. The subject property has not been under agricultural production since approximately 2007, so the nitrogen concentration is residual from previous production agriculture and organic decomposition of native grasses. Because septic effluent is composed predominately of ammonium(NH4),the pH, along with the CEC, are significant influences on the ammonium m6lecules. The pH of the soil profile is alkaline at 7.4. At this pH, ammonium will have a slight propensity to convert to ammonia. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules and is high at 26.7 meq/100g. NLS§3.3, SSS§ 5.3,5.4. Table 1 below summarizes the soil physical and chemical characteristics for the proposed filter bed soil: TABLE 1 SOIL PROFILE CHARACTERISTICS AND ANALYTICAL TEST RESULTS SAMPLE DEPTH AND SOIL SOIL NITRATE- pH,CATION EXCHANGE (SAMPLE ID ON TEST CLASSIFICATION NITROGEN CONTENT CAPACITY RESULT FORM) TKN CONTENT FILTER BED Clay Loam 13 ppm NO3-N 7.4 26.7 meq/100- 36"DEPTH (36'x) 760 mg/kg Chesney Consulting